The Internet of Things (“IOT”) refers to the network of systems, devices, and/or physical objects (collectively referred to as “systems”) existing in the real world, ranging from automobiles to heart monitors. These physical objects and/or devices are equipped and/or embedded with software, sensors, electronics, communication means and the like, that enable them to, among other things, communicate and exchange data. The number of systems that make up the Internet of Things is rapidly growing. Some industry analysts have estimated that the number of connected systems (in an industrial, consumer, government, medical, and business setting) may rise from five billion to one trillion over the next ten years. A substantial portion of that growth will be devices and systems using wireless communication, such as over cellular networks.
Common challenges to the adoption of new connected devices, among others, include operability (e.g., ease of interfacing and operating with legacy devices, including those of a vendor's own platform and various platforms offered by other vendors); efficiency (e.g., the cost of operating the connected devices, including the infrastructure cost); usefulness (e.g., the effectiveness of devices performing for their intended purposes); cost (e.g., cost to install, commission, update, and update the connected device and supporting infrastructure); and scalability. One particular intersection of these challenges is the communication protocol used in the control and management of such devices. The protocol defines, for example, how devices communicate among each other, what they communicate, when they communicate, and who or what they communicate with.
A popular communication protocol is the Hypertext Transfer Protocol-based (HTTP) REpresentational State Transfer (REST) application programming interface (API), also referred to as “HTTP RESTful API.” Two popular open standard formats of HTTP RESTful API include JavaScript Object Notation (“JSON”) and Extensive Markup Language (“XML”) data formatting. REST is a style of software architecture for distributed systems that may employ a standardized interface, such as HTTP. An application conforming to the REST constraints may be described as “RESTful”.
A protocol employing HTTP RESTful API and JSON/XML provides a flexible and open scheme for communication, though has its tradeoffs. For instance, though flexible because of its usage of human-readable text, the protocol is verbose and, thus, inefficient.
The operation of a communication protocol can be affected by the communication channel. For example, although HTTP is not restrictive as a communication protocol, the usage of HTTP is limited to unidirectional communications, in certain instances, due to traffic routing devices and security devices such as firewalls and Network Address Translation commonly employed within a computing and network infrastructure. HTTP polling is a typical technique used to overcome the unidirectional nature of HTTP across such Internet infrastructure, and the like. But using HTTP polling has a tradeoff of high reply-message latency responsiveness, high bandwidth consumption, and high server utilization.
There is a need, therefore, for a flexible, scalable and efficient protocols, such as or based on HTTP RESTful API, for machine-to-machine communications of connected devices. Moreover, there is a need for such protocols to be of low-latency and bidirectional.